Looking for logging into the Devise Facebook site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Devise Facebook site. After that you can login as usual with your login credentials.
https://qiita.com/kami_zh/items/94aec2d94a2b4e9a1d0b
https://qiita.com/nakki/items/b9339553dd9e28ab0db1
https://qiita.com/minakawa-daiki/items/e54ab46b382a19dcbbf4
https://github.com/plataformatec/devise/wiki/OmniAuth:-Overview
https://freesworder.net/rails-facebook/
https://medium.com/@chinnatiptaemkaeo/integrate-omniauth-facebook-to-rails-5-1389d760d92a
https://medium.com/@trydelight/facebook-authentication-with-devise-5b53d2f664ed
https://ticklecode.com/fb_omniauth/
https://codezine.jp/article/detail/10970
https://teratail.com/questions/105606
https://sadah.github.io/rails-training/ja/004_facebook.html
https://www.tech-tech.xyz/5508606.html
https://sourcey.com/articles/rails-omniauth-using-devise-with-twitter-facebook-and-linkedin